Dr. Heightmeyer (Claire Rankin) suggests everyone have a Sunday off, and this is what happens. Written by Martin Gero, Sunday first aired on 1 June, 2007.

Everyone has a relaxing plans in the works, Sheppard (Joe Flanigan) is teaching Ronon (Jason Momoa) about golf, McKay (David Hewlett) and Beckett (Paul McGillion) want to go fishing, Teyla (Rachel Luttrell) wants to go to the gym, and Weir (Torri Higginson) has a lunch date.

All of it is sidelined when an explosion rips apart the mess hall. There are fatalities and casualties, and now, not only are they mourning, they have to figure out what happened.

McKay learns that some of his staff have found and activated (and de-activated) an ancient device. It has created tumors inside the body, tumors that grow and explode! Can they find a way to stop it?

There’s a lot of fun to be had in this episode as we get a look at the way the characters interact off-duty. The narrative also folds back on itself so we get looks at various scenes and moments from different perspectives.

It’s a quieter episode with lots of character moments, and definitely has a lot of humor. It also has the requisite science fiction story to make it a Stargate story.

I also love seeing how everyone reacts to an emergency.

And then there’s the heartbreaking ending of the episode, that I am never ready for no matter how many times I’ve seen this episode. It’s such a sharp turn and reminds us how instantly things can change for those we love.

An utterly shattering episode that changes the face of the Atlantis expedition.

Submersion was written by Ken Cuperus and debuted on 8 June, 2007.

The expedition discovers an underwater Ancient base and Sheppard and his team head out to investigate.

Sheppard, Weir, McKay, Ronon, Teyla and a group of scientist pile into a puddle-jumper (Sheppard cautions them to behave unless he wants them to pull over) and off they go. What they aren’t ready for is the reveal that there is a Wraith Queen (Andee Frizzell) aboard.

Continuity ties in as Teyla’s ability to sense Wraith as well as being able to connect to them plays a huge part in the episode, especially when the Queen assumes control of her. Teyla insistts she can be of use, and keep the Queen’s control at bay.

She’s been at the bottom of the ocean for centuries, and there’s a deserted Wraith cruiser down there. Can the team not only deal with the Queen, but recover some Wraith tech?

There’s some truly creepy stuff here, in fact this may be the closest the series has gotten to a horror story. It’s a little haunted house mixed with possession and creature feature.

It’s a little creepy, and it brings the Wraith right back to the foreground after having been absent for the past number of episodes.

Next time we dive into the last two episodes of season three, which means there’s a cliffhanger coming our way.